Heat-sealing machine for bags, provided with bag locating means



Feb. 6, 1962 J. D. SYLVESTER ETAL 3,019,583

HEAT-SEALING MACHINE FOR BAGS, PROVIDED WITH BAG LOCATING MEANS FiledMarch 4, 1959 INVENTORS: mt JOHN D, m VESTQ J0/2W A KEZWAIV JR.

United States Patent 3,019,583 HEAT-SEALING MACHINE FOR BAGS, PROVIDEDWITH BAG LOCATING MEANS John D. Sylvester, Garden City, N.Y., and JohnD.

Keenan, Jr., Caldwell, N..l., assignors to Amseo PackagingMachinery,Ind, Long Isiand City, N.Y., a corporation of New York Filed Mar. 4,1959, Ser. No. 797,202 2 Claims. c1. 53-373 This invention relatesgenerally to heat-sealing apparatus, and has particular reference to amachine for sealing the mouth of a bag containing merchandise.

The type of bag to which the invention is primarily directed is composedof heat-sealable material such as polyethylene or the like, providedalong one edge with an opening or mouth and having a closed rear edgeopposite to the mouth edge. Usually the bag is substantiallyrectangular. it is sealed by subjecting the superposed walls of the bagmouth to the fusing action of a heat-applying element adapted to sealthe bag along a line adjacent to the enclosed merchandise. One type ofsealing machine that can be used for this purpose comprises a pair oftangentially arranged rollers at least one of which has a heated edge. Amoving conveyor can be employed to convey the bags from a relativelyremote bag-loading station to the heat-sealing station where thesuperposed walls of the bag mouth are subjected to the action of theheat-applying element. For example, the bag mouth walls may be directedto and through the nip of tangential rollers of the character mentioned.

It is a general object of the invention to provide an improved sealingmachine of this kind, whereby bags of the character referred to may bemore eifectively and reliably sealed in commercial quantities to produceuniformly good neat-appearing merchandise packages at rapid speed.

For the sake of appearance, and for other reasons, it is often desirablethat the bag mouth be sealed along a line which lies as close aspossible to the merchandise within the bag. Where bags contain productswhich have been folded, or which for other reasons vary in dimensions,such as sheets or other drygoods, the formationof seals which areuniformly close to the enclosed products presents a problem. Forexample, if the conveyor moves along a direction parallel to the sealingline, and if the bags to be sealed are laid successively on the conveyorat a bag-loading station with their rear edges along a longitudinalguide line, the bag mouth will be sealed close to the merchandise onlyin the case of the longest item; and for shorter items the seal will liecorrespondingly away from the enclosed merchandise. Folded items such assheets often vary in dimensions by as much as an inch or so, as a resultof which uniformly made packages cannot be produced with conventionalapparatus.

Even with a guide line, a further difiiculty is encountered in thesealing of bags containing articles such as mens shirts that are notstraight along opposite edges. For example, if the collar end of a shirtlies adjacent to the rear edge of the bag, it is difficult to set thisrear edge against a guide line in such a way that the bag will lieabsolutely straight. As a result, the seal that is ultimately formedalong the mouth edge of the bag is frequently askew, with consequentlack of uniformity in the merchandise packages produced.

It is an object of this invention to provide a practical solution forthese problems. More particularly, it is an objective of the inventionto provide an improved heatsealing apparatus in which a plurality ofmerchandisefilled bags, ready for sealing, may be advanced by a movingconveyor and may be automatically straightened. shifted crosswise on theconveyor, and otherwise conditioned to bring the walls of the bag mouthin each case into optimum relation to the heat-sealing element so as toform a heat-seal in close adjacence to the enclosed merchandiseregardless of its dimensional deviation from a standard average.

These desirable results are achieved, in accordance with this invention,by a special arrangement of guide rails which cooperate with each otherand with the succession of bags on the conveyor in an unusuallyeifective and novel manner. The improved structure is relatively simpleand inexpensive, easy to install and use, and reliable in operation.

A preferred way of achieving these objects and advantages, and suchother advantages as may hereinafter be pointed out, is illustrated inthe accompanying drawings, in which FIGURE 1 is a plan view of a sealingmachine installation embodying the features of this invention; and

FIGURES 26 inclusive are enlarged crosssectional views takensubstantially along the correspondingly-numbered planes indicated inFIGURE 1.

A flat belt-like conveyor 10 moving from left to right in FIGURE 1, isadapted to receive merchandise-filled bags in a loading region at theleft end of FIGURE 1, and to convey the bags successively to and beyonda sealing apparatus generally designated '11. The sealed merchandisepackages are removed from or discharged at the right end of theconveyor.

' It is to be understood that the representation of bags, and of partsof the apparatus, is in many respects schematic and exaggerated in theaccompanying drawings for the purpose of simplifying the illustrationand better explaining the nature of the invention.

The bags chosen for illustration are substantially rectangular, and aredepicted as containing merchandise in the nature of folded sheets orother drygoods. The bag 12 shown in FIGURE 2 has been filled at theloading station with a product 13, and has been laid upon the conveyor10 with its rear closed edge 14 against a guide rail 15. This rail issupported upon bracket 16 mounted on an element 17, which is rigidlysecured to the framework 18 of the conveyor. The guide rail 15 issubstantially parallel to the direction of movement of the conveyor. Itis positioned slightly above the level of the conveyor adjacent to theconveyor edge shown uppermost in FIGURE 1. At its terminal end it iscurved outwardly as indicated at 19.

Mounted alongside the conveyor 10 in a region closer to the sealingmachine 11 is another guide rail 20. This guide rail lies adjacent tothe opposite edge of the conveyor, and beyond the latter. It issupported upon brackets 21 carried on a shelf-like structure 22 securedto the framework 18 (see FIGURE 3). It is to be noted that the guiderail 15 terminates at a point prior to that at which the guide rail 20commences. Also, where the guide rail 20 commences, it may be curvedoutwardly as indicated at 23.

Between the guide rail 20 and the sealing machine 11 a blower nozzle 24is mounted above the level of the conveyor, as best indicated at FIGURE4. The function of this blower will be explained presently.

The sealing machine 11 chosen for illustration is of the rotary type.Its details have not been shown, since this kind of machine is known perse. It includes a pair of tangentially arranged rollers or wheels 25 and26 (FIG- URE 5), at least one of which (in this case, the roller 26) hasan attenuated edge 27. Also, at least one of the wheels (preferably theroller 26) is heated by suitable electrical means (not shown). Theeffect of these rollers is to fuse together and thus heat-seal the bagmouth walls that move between the rollers and are pinched. between theheated attenuated edge 27 and the anvil roller 25.

As has been stated, other types of heat-applying elements may beemployed to produce substantially the same result.

The conveyor moves from left to right as viewed in FIGURE 1, along adirection parallel to the line of the seal formed at the heatingstation. The filled bags at the loading station are all placed upon theconveyor with their rear edges against the guide rail 15, as shown bythe bag 12 in FIGURE 2. The two walls 28 of the mouth of the bag projectoutwardly beyond the adjacent edge of the enclosed product 13. The guiderail 15 is so located with respect to the location of the guide railthat all bags placed against the guide rail 15 will be so positionedthat their mouth edges will inevitably encounter the guide rail 20. Thelatter guide rail is in turn so located with respect to the heat-sealingelements 25, 26 that the bags encountering and moving past the guiderail 20 are straightened and shifted crosswise on the conveyor 10, thusbringing them into proper pre-determined relation to the heatingelements presently to be encountered. The

engagement of the mouth edge of a bag 29 with the guide rail 20 is shownin FIGURE 3.

During the sliding contact between the bag mouth and the guide rail 20the walls of the bag mouth may become crumpled or turned back, asindicated in FIGURE 3. To restore them to proper disposition, the blastof air emanating from the blower nozzle 24 serves as a means for layingthe walls of the bag mouth into smoothly extending relation forengagement by the rollers 25, 26. This is best indicated in FIGURE 4 inwhich the bagmouth walls 30 of a bag 31 are being blown into the desiredextended condition.

The bag-mouth walls presently enter the nip of the heating rollers,where they are subjected to the pinching action represented in FIGURE 5.Because of the prior proper positioning of the bag by the guide rail 20,the rollers create a seal line 32 (see FIGURE 6) which lies as closelyadjacent to the enclosed product as may be desired. This result isachieved regardless of the distance between the front edge 33 and therear edge 34 of the item within the bag (see FIGURE 6). The finishedmerchandise packages are thus uniformly compact, neatly sealed, and ofgood appearance.

The improved apparatus solves also the problem of straightening bagsthat may have been placed against the guide rail 15 in positions notaccurately straight. Provided the bags are not drastically askew in thefirst place, slight irregularities are corrected as the bags encounterand slide along the guide rail 20.

It is of advantage that the guide rails be mounted in adjustablefashion, to accommodate products of greater or lesser dimensions, and tobring the bags in each case successively into such a position as may bedesired with respect to the sealing element or wheels.

It is to be understood that many of the details herein described andillustrated, for the purpose of explaining the nature and purpose of theinvention, may be modified by those skilled in the art withoutnecessarily departing from the spirit and scope of the invention asexpressed in the appended claims.

What is claimed is:

1. In a machine for heat-sealing the mouth of a bag composed of limpnon-form-sustaining material and containing merchandise, said mouthlying along one edge of the bag and said bag having a rear edge oppositeto the mouth edge: a heat-applying element adapted to seal the bag mouthalong a line closely adjacent to the enclosed merchandise, a movingconveyor arranged to convey a bag along the direction of said seal linetoward and past said heat-applying element, a first guide rail alongsideone transverse edge of the conveyor and arranged above and parallel tothe direction of travel of said conveyor, said guide rail beingpositioned to be encountered by the mouthward edge of themerchandise-filled region of an approaching bag and serving to shift thebag on the conveyor in a crosswise direction to a predetermined positionrelative to said heat-applying element, a second guide rail alongsidethe opposite transverse edge of the conveyor in a region farther fromsaid element, said second guide rail being arranged above said conveyorand so located that the minimum crosswise distance between said rails isless than any bag dimension lying crosswise of the conveyor, whereby abag whose rear edge contacts said second rail will, regardless of thecrosswise merchandise dimension, have the mouthward edge of itsmerchandise-filled region positioned to encounter said first guiderails, and means between said first guide rail and said heat-applyingelement for laying the walls of the bag mouth into smoothly extendingrelation for engagement by said element.

2. In a heat-sealing machine, the combination of elements defined inclaim 1, in which said last-named means comprises a blower for directinga blast of air against said bag mouth walls in a direction generallyalong said walls.

References Cited in the file of this patent UNITED STATES PATENTS1,141,932 Byrnes June 8, 1915 1,445,899 McGregor Feb. 20, 1923 1,600,320Danquigney Sept. 21, 1926 1,770,379 Young July 15, 1930 1,855,767 NeumanApr. 26, 1932 2,015,507 Arnold Sept. 24, 1935 2,182,187 Wagner Dec. 5,1939 2,253,036 Kimple Aug. 19, 1941 2,597,634 Grevich May 20, 19522,645,396 Spohr July 14, 1953

